This applet Relative Motion on an Elevator Modelwritten by Francisco Esquembre Original applet http://www.compadre.org/osp/items/detail.cfm?ID=9974The Relative Motion on an Elevator model displays the relative motion as seen by two classical observers. The eight-years old kid Pepe Neurons plays yo-yo in an elevator with transparent walls in a shopping mall and his sister, Lola, looks at him from the ground floor of the shopping mall while he does so. Watch the motion of the kids, the elevator and the yo-yo from either Lola's or Pepe's perspective.

Now is available too portages(Brazil) version Translation by Ahmedelshfie, i attached the jar file.Enjoy!